M44 Head Gasket on M42?

[bmwman91]

So I am reassembling my engine this weekend. The new head gasket fits fine and all, but it did seem to cover up a few holes. Anyway I checked the part number and it seems to be a head gasket for an M44. Will this work with the M42 block/head, or did oil and coolant passages get moved around? My assumption as to why I was given this gasket is that it is because this engine is bored out to 86.97mm and the M44 HG is for a slightly larger bore (85mm vs 84mm) than the M42 HG.

Silly me, I of course assembled the head and a couple of things before thinking to ask, but I am not proceeding any further until I figure this out. The only real difference that I can find is that it covers up the top 3 small holes between the cylinders. This is going based on part photos on Pelican Parts.

Thanks!

[Warsteiner]

 I used the 2.07mm M44 gasket. I didn't see a major issue and don't remember that it actually blocked anything. Can you take a pic of what you think its blocking?

Cheers,
~Ralph

[bmwman91]

Yeah from looking at the imprints on the block in some pics I took when I pulled the head, the engine had an M44 gasket in there before. I'll circle the 3 small holes that it blocks. I assume that these don't do anything, because if they were oiling holes I think that the valve train would sieze lol.

Here is the M42 gasket:
http://www.ecstuning.com/Search/11121721550/ES18248/

Here is the M44 gasket:
http://www.ecstuning.com/Search/11121433951/ES18139/

These are the holes that the gasket blocks:




This thread seems as good as any to give some status updates on my project too.

I got it all back together today, mostly. The injectors I received don't seem to fit though. They are later EV6 style ones, and the little slots that the metal clips grab are too far from the fuel rail so the clips can't actually secure them to the rail. Sooooo...looks like I have a phone call to make on Tuesday lol. HOPEFULLY there are some longer clips out there that will do the job. Did M44 engines use different/longer clips?

These are 24# injectors with quad-pintles.






Here are the pistons and block after some cleaning. I used a putty knife and shop-vac to get most of the crud off (the carbon on the pistons came right off) and then some lacquer thinner to deal with what remained. Then, I finished off with a clean rag and some isopropyl alcohol to remove any remaining residue. The putty knife also worked well to de-burr piston #3 which had some slight damage from the broken intake valve.


This is what it looked like before I started.


I was also a little worried about the metal paint stuff on the HG. It looks like MM coats the HG with a metalized paint (the first one had this stuff on it too and I had to scrape it off the block). It seemed to be flaked off in a few places around cylinders 2 and 4 (exposed gold areas). I assume that this is a non-issue, given how thin it is and how much pressure is clamping the head onto it? My paranoia seems to be a little heavy lol. I vacuumed out the head bolt holes, although I was tired and didn't remember to blow them out and check for fluid. I coated all of the bolts with ARP moly lube prior to installation, and they all felt like they torqued down the same so I doubt that any of them were hydro-locked with coolant or anything. I set them all to 25ft-lbs in the specified order (god only knows how accurate that torque wrench is anymore) and then eyeballed the two 90 degree turns. Hopefully it all works out.


I had a familiar mini-project too. When I was reinstalling the top bolt for the driver's side chain guide, the threads stripped. Thankfully, this is really easy to deal with without taking anything apart. Just get a shop vac hose down in there, drill, tap, clean and stuff a helicoil in!


The repaired head. Again, nit-picking. Are the cam bearing caps directional? One seemed to be "upside down" relative to all the others (rearmost exhaust cam cap). I turned the engine over by hand a good 8 times and it felt smooth as butter, so at least the timing is on. MM made some very good, clear TDC marks for the cams so I could get things aligned easily.


When the car WAS running a few months ago, I seemed to be getting a speed related vibration, typically at 75MPH or more. I suspected that maybe I got the driveshaft halves out of phase or something. When I checked, the halves seemed to be in alignment. One of my four wheels seems to be missing a weight, and the tires are old, hard rubber and close to needing replacement, so maybe it is just that.


I DID forget to bias the CSB 5mm toward the front last time, so I took care of that this time.


So anyway, everything is together except the fuel rail and upper intake components. I will add coolant then too. The oil is in (Castrol 10W-60 TWS full synthetic). Jim at MM did a big oil study and concluded that this stuff offers the best protection for any non-race application.
http://www.pelicanparts.com/More_Info/07-51-0-009-420-M906.htm?Castrol%20Motor%20Oil%20%28API%20SJ%2FCF%29%2C%20TWS%20Motorsport%2C%2010W-60%20Full%20Synthetic%20%281%20liter%29

[bmwman91]

I have read around the web a bit, and it looks like a number of M42 turbo guys have used the M44 head gasket. Anyway, given how many miles I put on the engine when it already had an M44 HG in there (unbeknownst to me) I'd say that it is probably fine. I still want to know WTF those 3 small holes are for lol.

[MLM]

Looks awesome.

On the injector front im in a similar position regarding the retaining clips. I intend to use honda type R injectors for their cc rating and multi port head. These injectors look the same once inserted into the rail where the clip dosnt reach. I have looked for clips but as yet have not found any.

But I am starting to think they are not required. Once installed the injector will not fall out as it is encapsulated at both ends by a fuel rail and intake manifold. The clip serves as an excellent aid during assembly in a factory application but appears some what redundant after that. Given time patience and careful checking (luxuries a factory typically wont have) the injectors could be installed minus the clip without an issue.

[bmwman91]

I am not 100% sure that I trust the injector to remain constrained by the intake manifold. It looks like in order to do that, the O-ring will be almost entirely through the injector port and maybe not sealing super well. I am also not sure that the injector will remain seated in the rail when inserted that far into the manifold (didn't check yet).

I'll wait and see what MM recommends.

[bmwman91]

I spoke with MM today.

They said that my concerns over the chipped paint stuff on the head gasket are a non-issue since the stuff is there mainly to seal up the water holes. It should not have any effect on the HG's metal seals.

As for the injectors, they are sourcing some extended clips for the injectors. While there are other ones out there, including some that Warsteiner recommended, apparently these are pretty well proven and MM has used them with a lot of success. The clips that they are trying to get a hold of are from a 1970's Bavaria of some sort. They aren't 100% sure that these are the proper length, and if they aren't they will either TIG some custom ones up for me or explore other injector options. I'll keep you guys posted!

[slong27]

I remember reading that if you are using the ARP head bolts you can step up to (I believe that it was 64ft lbs) and not have to do the 90 + 90 step. Is that not true?

[bmwman91]

I got two recommendations from MM. Jim, the owner, recommended going up to 64 ft-lbs in 3 steps. Another guy there, who does much of the assembly work, said to do 25 ft-lbs and then 90deg + 90 deg. So, I used 90 deg (eyeballed as best I could). This may be like "breaking in an engine" where there are a ton of methods, and all of them work. As long as you are not grossly exceeding the bolt's strength or over-stressing the head, you are probably fine I'd think.

[wazzu70]

Using the angle method gives a much more consistent clamping force.

The issue going of torque and not angle is friction is in the equation and adds to the torque value.

[slong27]

That does make sense if you think about it. Probably will end up giving more accurate or true torque values if you go the 90 + 90 method. Have no idea how much difference there might be though.